An elderly woman went missing in Riverside yesterday afternoon, and family members and friends are gathering at 9 a.m. sharp to try and find her.

Jean Taber, an 82-year-old who suffers from dementia, was walking her springer spaniel south on Route 104 near the mobile home park where she lives — Riverwoods — about 2 p.m. yesterday. She hasn’t been seen since.

She was wearing a black vest, black dress and family members say she may be in need of medical attention. She is white, and is listed at 5-foot-10, 110 pounds with red hair and hazel eyes. Her dog is white and tan-colored.

New York State Police is leading the investigation, and is expected to issue a statement shortly this morning.

Mark Norton, Ms. Taber’s grandson, said the family has been working with the state police and Long Island Search and Rescue to find Ms. Taber, and will be meeting at the mobile home park’s clubhouse at 9 a.m. to conduct a search for her.